A week after GM announced that it will idle its Hamtramck plant, Fiat Chrysler said it will build a new Jeep at its idled Mack Avenue Engine Plant II. This could add up to 400 jobs at the plant on Detroit’s East Side. It’s part of a larger facility that employs 5,000 workers and will be Detroit’s only remaining automotive factory when the GM facility closes. While the additional jobs won’t have much of an impact on the overall Detroit economy, they will offset some of the GM cuts.